Portable shelter



FIG. 1 is a front perspective view of a portable shelter;

FIG. 2 is a top side view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a left side view thereof; and,

FIG. 7 is bottom view thereof.

Any broken lines shown in the drawings represent portions of theportable shelter that form no part of the claimed design.

CLAIM The ornamental design for a portable shelter, as shown anddescribed.